Air-Oil Separator Threaded Seal to Prevent O-Ring Assembly Leaks

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Solution Overview

Problem

Existing air/oil separator devices face challenges with O-ring sealing issues, including increased assembly difficulty due to friction, potential damage during assembly, wear leading to leaks, and the risk of re-entrainment of separated oil back into the air flow, which complicates the separation process and affects the reliability of the separation device.

Innovation Solution

The solution involves a separating device design without an O-ring, utilizing a continuous and uninterrupted thread on the housing cover and connecting element for a tight seal, with a labyrinth seal and a sealing and damping element to prevent liquid outflow and ensure a reliable separation of oil from air, enhancing the sealing mechanism and assembly ease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an O-ring is used to seal between the housing cover and connecting element, then sealing is achieved, but assembly difficulty increases due to friction and the O-ring may be damaged during assembly

Engineering Contradiction:
Improvesealing reliabilityVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes the O-ring sealing element from the system and replaces it with a direct thread-to-thread sealing mechanism between the housing cover and connecting element. This eliminates the O-ring that causes assembly friction and potential damage while maintaining sealing functionality through the threaded connection itself.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a sealing element integrated into the threaded connection structure, where the seal is formed by the mating threads themselves rather than a separate O-ring. This intermediary sealing mechanism is built into the connection geometry, allowing sealing without the friction and damage issues of traditional O-rings.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If an O-ring is used to retain separated oil, then oil retention is achieved, but the sealing surface may wear down over time leading to leaks

Engineering Contradiction:
Improveoil retention reliabilityVSAvoidservice life of sealing surface
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent eliminates the separate O-ring that relies on a sealing surface, and instead creates oil retention through the threaded connection structure itself. The seal is formed by the engaging threads between housing cover and connecting element, removing the wear-prone sealing surface and O-ring combination from the system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The threaded connection performs dual functions: mechanical fastening and sealing. The same threads that secure the housing cover to the connecting element also create the seal that retains oil, eliminating the need for a separate sealing surface that can wear down over time.

Inventive Principle:
Principle #25Self-service

3Reliability

If a seal is arranged between the lower end disk and radially outer circumferential side of the connecting element, then oil is retained, but mounting difficulty increases due to additional friction

Engineering Contradiction:
Improveoil retentionVSAvoidmounting ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent combines the sealing function with the mounting thread structure. The seal is integrated into the threaded connection between the housing cover and connecting element, so that the same components that perform mechanical fastening also provide sealing. This eliminates the need for a separate seal between the lower end disk and connecting element, reducing mounting friction while maintaining oil retention.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If the thread is designed for tight engagement to prevent leaks, then sealing is improved, but assembly becomes more difficult due to increased tightening torque

Engineering Contradiction:
Improveleak preventionVSAvoidassembly difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent removes the separate seal that would require high tightening torque to compress, and instead creates sealing through the threaded engagement itself. The seal is formed by the geometry of the mating threads, which naturally create a tight seal through their interlocking structure without requiring excessive tightening force.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design significantly reduces the risk of oil re-entrainment, simplifies assembly, and provides a reliable sealing mechanism, ensuring efficient separation of oil from air and minimizing leakage, thereby improving the operational reliability of the air/oil separator device.

Implementation Method 1

the friction of the O-ring 320' must be overcome to engage the housing cover thread 36' with the thread 232' of the connecting pipe fitting

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a thread associated with the first gas passage, wherein the thread of the housing cover is designed for screwing onto a thread of the connecting element

Methodology Applied
Scientific EffectMechanical Fastener: Mechanical Fastener

Implementation Method 3

utilizing a continuous and uninterrupted thread on the housing cover and connecting element for a tight seal, with a labyrinth seal and a sealing and damping element to prevent liquid outflow

Methodology Applied
Scientific EffectLabyrinth seal:

Implementation Method 4

a sealing and damping element to prevent liquid outflow and ensure a reliable separation of oil from air

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3366363B1Separation device for separation of fluid from gas and separation element and connecting element for such a separation device
Publication Date: 2021.03.10 MANN HUMMEL GMBH
  • EP3366363B1 patent drawingFigure 1
  • EP3366363B1 patent drawingFigure 2
  • EP3366363B1 patent drawingFigure 3

AI summary

The invention describes a separating element (100) suitable for a separating device (300), comprising: - a housing (90) with at least one filter element (10, 20) arranged in the housing (90) for separating at least one liquid from a gas; and - a housing cover (30) designed to close an end face of the housing (90) with: -- at least one first gas passage (32) arranged centrally, in particular coaxially, on a connection device with respect to a mounting axis (40) of the separating element (100); -- a thread (36) associated with the first gas passage (32), wherein the housing cover thread (36) is designed for screwing onto a thread (232) of a connecting element (200) designed for connecting the separating element (100) to the connection device; and -- at least one second gas passage (34) located radially outside the first gas passage with respect to the mounting axis (40) of the separating element (100). gas passage (32) is arranged.In order to further develop this separating element (100) in such a way as to exclude potential malfunctions of the separating element (100) and to facilitate the assembly of the separating element (100) in the separating device (300), it is proposed that - the first gas passage (32) and the second gas passage (34) are the only openings of the housing cover (30) and the housing cover (30) is otherwise completely closed and - the housing cover thread (36) is designed for sealing engagement with the connecting element thread (232).